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Support loading WAV audio

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This commit is contained in:
Nikita Lisitsa 2022-10-07 23:40:03 +03:00
parent e7c999c3dd
commit 2c59879630
2 changed files with 56 additions and 7 deletions
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2
libs/audio/include/psemek/audio/engine.hpp
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@ -21,8 +21,8 @@ namespace psemek::audio
engine();
~engine();
track_ptr load_raw(float const * data, std::size_t sample_count, bool copy = true);
track_ptr load_raw(util::span<float const> data, bool copy = true);
track_ptr load_wav(util::span<char const> data);
channel_ptr output();

61
libs/audio/source/engine.cpp
View file

@ -3,6 +3,8 @@
#include <psemek/sdl2/init.hpp>
#include <psemek/log/log.hpp>
#include <psemek/prof/profiler.hpp>
#include <psemek/util/at_scope_exit.hpp>
#include <psemek/util/to_string.hpp>
#include <SDL2/SDL.h>
@ -77,6 +79,41 @@ namespace psemek::audio
std::shared_ptr<track_data> data_;
};
std::vector<float> convert_audio(SDL_AudioSpec const & spec, std::uint8_t * samples, std::size_t length)
{
if (spec.channels > 2)
throw std::runtime_error(util::to_string("Can't convert audio with ", static_cast<int>(spec.channels), " channels"));
if (spec.freq != 44100)
throw std::runtime_error(util::to_string("Can't convert audio with frequency ", spec.freq));
if (spec.format != AUDIO_S16SYS)
throw std::runtime_error(util::to_string("Can't convert audio with format ", spec.format));
auto p = reinterpret_cast<std::int16_t *>(samples);
std::vector<float> result;
if (spec.channels == 1)
{
result.resize(length);
for (std::size_t i = 0; i < length / 2; ++i)
{
float v = (p[i] * 2.f + 1.f) / 65536.f;
result[2 * i + 0] = v;
result[2 * i + 1] = v;
}
}
else
{
result.resize(length / 2);
for (std::size_t i = 0; i < length / 2; ++i)
result[i] = (p[i] * 2.f + 1.f) / 65536.f;
}
return result;
}
}
struct engine::impl
@ -154,26 +191,38 @@ namespace psemek::audio
engine::~engine() = default;
track_ptr engine::load_raw(float const * data, std::size_t sample_count, bool copy)
track_ptr engine::load_raw(util::span<float const> data, bool copy)
{
if ((sample_count % 2) != 0)
if ((data.size() % 2) != 0)
throw std::runtime_error("bad sample count");
auto tdata = std::make_shared<track_data>();
if (copy)
{
tdata->storage.assign(data, data + sample_count);
tdata->storage.assign(data.begin(), data.end());
tdata->samples = tdata->storage;
}
else
tdata->samples = {data, data + sample_count};
tdata->samples = data;
return std::make_shared<track_impl>(std::move(tdata));
}
track_ptr engine::load_raw(util::span<float const> data, bool copy)
track_ptr engine::load_wav(util::span<char const> data)
{
return load_raw(data.data(), data.size(), copy);
SDL_AudioSpec spec;
std::uint8_t * samples;
std::uint32_t length;
if (!SDL_LoadWAV_RW(SDL_RWFromConstMem(data.data(), data.size()), 1, &spec, &samples, &length))
sdl2::fail("SDL_LoadWAV_RW failed:");
util::at_scope_exit release_samples([samples]{ SDL_FreeWAV(samples); });
auto tdata = std::make_shared<track_data>();
tdata->storage = convert_audio(spec, samples, length);
tdata->samples = tdata->storage;
return std::make_shared<track_impl>(std::move(tdata));
}
channel_ptr engine::output()